Mirror of forum.nim-lang.org

3589 :: javascript new object

• domogled (orginal) [2018-02-28T14:56:47+01:00] view original

  Please,

  I can this javascript code

  
  var scene = new THREE.Scene();
  Run

  using in nim js. Defing type

  type
      THREE* = ref THREEObj
      THREEObj {.importc.} = object
          Scene* {.importc.}: proc(): void
  
  {.push importcpp.}
  Run

  # var scene = new THREE.Scene();
  var scene = THREE.Scene()
  Run

  
  Error: object constructor needs an object type
  Run

  Why create constructor?

  thanks

---

• domogled (orginal) [2018-02-28T16:14:02+01:00] view original

  OK,

  Im considering that jsffi is good way.

  var scene = jsnew(Scene())
  var geometry = jsnew(BoxGeometry( 1, 1, 1,0,0,0 ))
  Run

  will transpiled as

  
  var scene_69011 = (new THREE.Scene());
  var geometry_69079 = (new 1.0000000000000000e+00.THREE.BoxGeometry(1.0000000000000000e+00, 1.0000000000000000e+00, 0.0, 0.0, 0.0));
  
  Run

  typeddeclaration is

  proc Scene*(): JsObject {. importcpp: "THREE.Scene" .}
  proc BoxGeometry*(width,
                  height,
                  depth,
                  widthSegments,
                  heightSegments,
                  depthSegments : float): JsObject {. importcpp: "THREE.BoxGeometry" .}
  Run

  Do you know, why is constructor with parameters wrong transpiled?

  thanks

---

• stisa (orginal) [2018-02-28T17:48:36+01:00] view original

  From the manual :

  
   proc cppMethod(this: CppObj, a, b, c: cint) {.importcpp: "#.CppMethod(@)".}
   Produces:
   x->CppMethod(1, 2, 3)
   
   As a special rule to keep backwards compatibility with older versions of the importcpp pragma,
   if there is no special pattern character (any of # ' @) at all, C++'s dot or arrow notation is assumed,
   so the above example can also be written as:
   
   proc cppMethod(this: CppObj, a, b, c: cint) {.importcpp: "CppMethod".}
  
  Run

  The same thing is happening in your snippet.

  Try using importcpp: THREE.BoxGeometry(@)

  PS: I think you don't really need jsnew, you can just do importcpp: "new THREE.BoxGeometry(@)"

---